In yet another indication of a pathogen's role in the increase of obesity cases worldwide, a study conducted on Australians showed that the virus Ad-36 might have a hand in causing weight gain. Ad-36, which is a human adenovirus, causes eye infections, colds, and diarrhea.
Under the study, researchers from the University of Wisconsin at Madison, led by Richard Atkinson, conducted blood tests on around 2,000 Australians. The results showed that 20 per cent of the study subjects had been exposed to Ad-36. Another study by the same team, conducted on 500 Americans, had shown that around 30 per cent of those who were classified as obese had been infected by the virus, as against 11 per cent of those who had normal body weight.
Laboratory experiments have shown the presence of Ad-36 in the fat cells of animals and humans. In addition, the virus has been found to aid the conversion of pre-fat cells to fat cells. “I believe obesity is a complex disease of many causes, one of which is viral infection,” Atkinson said.
He added that in the study of Americans, the researchers had also studied cases of 26 pairs of twins, one of whom had been exposed to Ad-36. “And just as we predicted, the infected twins were heavier and fatter,” Atkinson explained.
Among animals too the instances of obesity rise with exposure to the adenovirus. Experiments with chickens and mice had shown that Ad-36 infection led to weight gain. What's more, the virus spread from one animal to another easily. “The uninfected animals got infected and got fat,” Atkinson said. He added that study explains the rising instances of obesity in Australia and also in other parts of the world.
Defined as excessive body weight, obesity is the cause of a number of diseases including cardiac ailments, diabetes, arthritis and even cancer. Besides overeating, it is caused by factors like sedentary lifestyle, lack of sufficient sleep and physical activity, among others. The instances of obesity have been growing alarmingly fast throughout the world with many developing countries also reporting high instances of excess body weight among its citizens.
